Direct Access to Thiocyano-Thioesters from Cyclic Thioacetals via Photoredox Catalysis: An Introduction of Two Functional Groups in One Pot.

The cyanation of organic compounds is an important synthetic transformation and mainly relies on a toxic CN source. Undeniably, thiocyanate salt has emerged as a very mild and environmentally benign CN source, yet its synthetic utility for cyanation is highly limited to very few types of organic compounds. Herein, we report the direct cyanation of cyclic thioacetals for accessing compounds with two different functional groups (thiocyano-thioesters) in one pot using sodium thiocyanate via photoredox catalysis. The protocol has been further extended for the direct cyanation of disulfides and diselenide to access aryl thiocyanates and aryl selenocyanate. A plausible mechanism has been proposed based on a series of control experiments, cyclic voltammetry and Stern-Volmer studies.